1). Field of the Invention
This invention relates to semiconductor processing, and more specifically to a method for improving nitrogen profile in plasma nitrided gate dielectric layers.
2). Discussion of Related Art
Gate dielectric films that are used for transistor fabrication are often nitrided with nitrogen ions to increase their capacitances. A small fraction of nitrogen in such a film is lost after being incorporated into the film before further processing. The total nitrogen content may differ from wafer to wafer because of differences in process delay, so that transistors of different wafers have dielectric layers with dramatically different capacitances.